Package bag and method for producing same

ABSTRACT

A manufacturing method of a package bag ( 10 ) according to the present invention includes: a cured portion forming step of forming a cured portion ( 15   a,    15   b ) on at least one side of a forming position of a rib ( 14 ) by crystallizing at least a portion of a resin constituting a film ( 11 ) by heating and cooling the film ( 11 ); and a rib forming step of forming a rib ( 14 ) by pressing the film ( 11 ) using concave and convex molds. According to the present invention, it is possible to maintain an opening state of a spout ( 12 ). Further, since additional material is not required, it is possible to suppress increase in the thickness of the package bag ( 10 ) and to reduce the bulkiness of the package bags.

TECHNICAL FIELD

The present invention relates to a package bag having a spout which isdefined by a pair of flow passage forming sealing portions which areformed by sealing two films at both side portions of a flow passage, anda manufacturing method thereof.

BACKGROUND ART

A package bag provided with a spout has been widely used as, forexample, a package bag which accommodates contents for refill, in orderto easily discharge the contents therefrom.

Patent Document 1 discloses a bag having a reinforcement mechanismconstituted by two linear deformations which are formed by performingdeformation processing on a film, in order to prevent bending of a spoutportion.

Patent Document 2 discloses a package bag provided with a reinforcementlayer formed on a base material having a flow passage introductionportion of a spout, a flow passage of the spout, and the like, byapplying curable resin to the base material, or by adhering areinforcement piece to the base material.

Patent Document 3 discloses a pouch container having: a planarprotruding processed portion which is formed in a region where anopening cutting line is disposed; and a protruding processed portionwhich protrudes outward from a wall of the pouch, such as a first linearprotruding processed portion which is formed in a center line direction,second linear protruding processed portions which are formed in bothsides of the first protruding processed portion along the firstprotruding processed portion, and a third linear protruding processedportion which is formed in a direction intersecting the center line.

CITATION LIST Patent Document

Patent Document 1: Japanese Unexamined Patent Application, FirstPublication No. H7-2260

Patent Document 2: Japanese Unexamined Patent Application, FirstPublication No. 2004-338753

Patent Document 3: Japanese Unexamined Patent Application, FirstPublication No. 2007-276837

SUMMARY OF INVENTION Technical Problem

The package bag disclosed in Patent Document 1 does not requireadditional materials used for improving the spout efficiency. However,the opening degree of the spout changes depending on the flow amount ofthe contents which passes through the spout. Therefore, if the residualamount of the contents decreases, the flow amount of the passingcontents also decreases, and it thereby becomes difficult to maintainthe opening state of the spout. Specially, in the case of a large-sizedpackage bag for business use, compared with a small-sized package bagfor home use, a package bag capable of maintaining the opening state ofthe spout until almost no residual liquid remains is desired from theviewpoint of a reduction of cost associated with loss of the residualliquid or working time.

Further, if the reinforcement layer is separately provided as isdisclosed in Patent Document 2 or many protruding processed portions areprovided as is disclosed in Patent Document 3, since the thickness ofthe package bag increases, the package bags when the empty bags areboxed becomes bulky.

The present invention was devised in view of the above circumstances,and has as an object the provision of a package bag which can easilymaintain an opening state of a spout and which can suppress increase inthe thickness of the package bag and reduce the bulkiness of the packagebags even when the spout is reinforced, and a manufacturing methodthereof.

Solution to Problem

In order to achieve the above-described objet, the present inventionadopts the following means.

The present invention provides a manufacturing method of a package bagincluding: a spout defined by a pair of flow passage forming sealingportions which are formed by sealing two films at both side portions ofa flow passage; a groove rib formed so as to protrude outward of thefilm and extend along the flow passage; and a cured portion formed on atleast one side of the rib by crystallizing at least a portion of a resinconstituting the film, and the manufacturing method including: a curedportion forming step of forming the cured portion on at least one sideof a forming position of the rib by crystallizing at least the portionof the resin constituting the film by heating and cooling the film; anda rib forming step of forming the rib by pressing the film using concaveand convex molds.

The rib may have a width of 0.5 to 3 mm and a height of 0.5 to 3 mm.

In the rib forming step, the rib may be formed without heating.

In the cured portion forming step, the film may be cooled by molds,whose shape corresponds to the shape of the cured portion, abutting bothsurfaces of the film, and a roughening processing may be performed on anouter surface of the cured portion of the film by using a mold having anabutting surface which abuts an outer surface of the film and on which asandblast processing is performed.

The manufacturing method may further include a step of providing anopening assisting line which intersects the rib.

The present invention provides a package bag including: a spout which isdefined by a pair of flow passage forming sealing portions which areformed by sealing two films at both side portions of a flow passage; agroove rib which is formed so as to protrude outward of the film andextend along the flow passage; and a cured portion which is formed on atleast one side of the rib by crystallizing at least a portion of a resinconstituting the film.

The rib may have a width of 0.5 to 3 mm and a height of 0.5 to 3 mm.

The package bag may further include an opening assisting line which isprovided so as to intersect the rib.

An outer surface of the cured portion of the film may be roughened.

The film may be formed in a substantially rectangular shape; among thepair of flow passage forming sealing portions, one flow passage formingsealing portion may be provided on a first side of the film, and theother flow passage forming sealing portion may be provided on a secondside of the film adjacent to the first side; and at least one of theribs may be disposed on an intersection point between a line passingthrough a position of the flow passage forming sealing portion on thefirst side which is the closest to a third side opposite to the firstside and extending substantially parallel to the third side, and a linepassing through a position of the flow passage forming sealing portionon the second side which is the closest to a fourth side opposite to thesecond side and extending substantially perpendicular to the third side.

Advantageous Effects of Invention

According to the present invention, by providing the cured portionformed on one side or both sides of the groove rib, which is formed soas to protrude outward of the film and extend along the flow passage, bycrystallizing at least a portion of resin constituting the film, it ispossible to maintain an opening state of the spout. Further, sinceadditional material is not required, it is possible to suppress increasein the thickness of the package bag and to reduce the bulkiness of thepackage bags.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view showing an example of a package bag according tothe present invention.

FIG. 2A is a sectional view taken along the line A-A in FIG. 1.

FIG. 2B is a partially enlarged view of a part B in FIG. 2A.

FIG. 3A is a front view showing an example of a state where the packagebag shown in FIG. 1 is opened to spout liquid contents therefrom.

FIG. 3B is a sectional view taken along the line C-C in FIG. 3A.

FIG. 4 is an explanation drawing of a step of forming a rib and curedportions in a film in a manufacturing method of a package bag accordingto the present invention.

FIG. 5 is a partially sectional view of a spout and the vicinity thereofshowing a state where the empty package bags according to the presentinvention are piled.

FIG. 6 is a partially sectional view of a spout and the vicinity thereofof a first modification example of the package bag according to thepresent invention.

FIG. 7 is a partially sectional view of a spout and the vicinity thereofof a second modification example of the package bag according to thepresent invention.

FIG. 8 is a front view showing an example of a state where an openingassisting line which intersects the rib is provided in the package bagaccording to the present invention.

FIG. 9 is a front view showing an example of a state where the rib isdisposed at a predetermined position in the package bag according to thepresent invention.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an embodiment of the present invention will be describedwith reference to the drawings.

As shown in FIGS. 1, 2A and 2B, a package bag 10 according to thepresent embodiment is a standing pouch which is constituted by: twosheets of body films 11 and 11 having the same planar shape; and abottom film 16 which is folded in half along a folding line 16 a as acenter line. As shown in FIG. 1, the bottom film 16 is folded in a statewhere the folding line 16 a is disposed thereinside, and is interposedbetween lower portions of the pair of body films 11 and 11. Note that anup-and-down direction on the paper in FIG. 1 is defined as a verticaldirection in a state where the package bag 10 stands.

Side edge sealing portions 11 a and 11 b are formed in both side edgeportions of the package bag 10, and a bottom sealing portion 16 b isformed in a lower portion of the package bag 10 by heat-sealing loweredge portions of facing surfaces of the bottom film 16 and each of thebody films 11 and 11.

A laminated film is used for forming the body film 11 and the bottomfilm 16. As the laminated film, a conventionally used film, for example,a film in which a film formed of biaxially-stretched polypropylene,biaxially-stretched polyamide, biaxially-stretched polyester, or thelike may be used as a base film, and a polyolefin-based resin such aslow-density polyethylene, linear low-density polyethylene,ethylene-vinyl acetate copolymer, or polypropylene may be laminated as asealant layer on the base film, is used. As a method of manufacturing alaminated film, dry-laminating, extrusion-laminating, co-extruding, orthe like may be used. In order to improve the adhesive strength, anadhesive agent, an anchor agent or the like may be disposed between thebase film layer and the sealant layer. In this case, in order to improvethe strength of the package bag, a plurality of base films may belaminated. Alternatively, in order to improve the barrier properties forgas or ultraviolet rays, a metallic foil such as an aluminum foil, ametal deposition layer, an inorganic deposition layer such as ceramic,ethylene-vinyl alcohol copolymer film or the like may be laminated.

The dimension of the package bag 10 is not particularly limited.However, it is preferable as a refill container to set the height of thepackage bag 10 to around 100 to 500 mm, the width (the maximum widthbetween the both side edges) of the package bag 10 to around 70 to 300mm, and the filled amount of the contents to around 100 to 5,000 cm³.

As shown in FIG. 1, a spout 12 is provided in an upper corner portion ofthe package bag 10. The spout 12 has a flow passage 13 which extendsdiagonally above.

In the present embodiment, flow passage forming sealing portions 13 aand 13 b are formed by partially heat-sealing the body films 11 and 11so as to continuously extend from an upper portion of the side edgesealing portion 11 a. As shown in FIG. 3A, the flow passage formingsealing portions 13 a and 13 b define both side portions of the flowpassage 13 when the tip end portion of the spout 12 is removed to openthe flow passage 13. That is, the flow passage 13 of the spout 12 isformed by an unsealed portion between one flow passage forming sealingportion 13 a and the other flow passage forming sealing portion 13 b.

The tip end portion of the flow passage 13 is closed by a close sealingportion 13 c. A filling opening 17 is opened between the flow passageforming sealing portion 13 b and the side edge sealing portion 11 b, andthe contents are filled into the package bag 10 through the fillingopening 17. After filling the contents, the filling opening 17 is closedby heat-sealing the body films 11 and 11 at circumferential edges of thefilling opening 17 to form an upper sealing portion 18 (refer to FIG.3A).

In order to easily open the spout 12, an opening assisting line 12 awhich is made of, for example, a half cut groove which intersects theflow passage 13 and is formed by a laser, a tub (grip) 12 b which isformed in one edge side of the opening assisting line 12 a by a cut-outline (penetration cutting) 12 c, and the like may be provided in thespout 12.

Further, as shown in a package bag 100 in FIG. 8, if the openingassisting line 12 a is provided so as to intersect a rib 14 (describedlater), since the rib 14 is also cut at the time of opening, the rib 14is included in a cut surface. Therefore, it is possible to easilymaintain an opening state of the flow passage 13 after opening. Notethat in the package bag 100 shown in FIG. 8, the same constituentelements as those of the package bag 10 shown in FIG. 1 are designatedby the same reference numerals.

In order to prevent the opening assisting line 12 a from accidentallytearing in an unused state by getting caught by the tub 12 b, it ispreferable to provide one or more uncut portions (not shown) in thecut-out line (penetration cutting) 12 c. The width of the uncut portionis set depending on the material of the body film 11. However, the widthof the uncut portion may be set to around 0.5 to 1.5 mm in order toeasily tear the uncut portion in hands at the time of opening.

The package bag 10 according to the present embodiment is provided with:the groove rib 14 which is formed along the flow passage 13 of the spout12 by outwardly protruding a portion of the film 11; and cured portions15 a and 15 b which are formed in both sides of the rib 14 bycrystallizing at least a portion of resin constituting the film 11.

As shown in FIG. 2B, the rib 14 is formed by providing a plurality oflinear deformations 14 a, 14 b, 14 c, and 14 d in the film 11,processing the film 11 in a groove shape along the linear deformations14 a, 14 b, 14 c, and 14 d, and making creases to the folded portions.The rib 14 and the linear deformations 14 a, 14 b, 14 c, and 14 d of therib 14 are formed by performing pressing processing on the film 11 byconcave and convex molds. When viewing from the outside of the bag, thelinear deformations 14 a and 14 b in the inner side are mountain folds,and the linear deformations 14 c and 14 d in the outer side are valleyfolds.

When forming the rib, it is preferable to apply pressure to the filmwithout heating (for example, at a normal temperature of around 10 to 40degree C.). By forming the rib without heating, since the fluidity ofthe resin constituting the film 11 is low, it is possible to easily forma fine rib 14. Further, it is possible to form a strong rib 14 which ishardly crushed since the creases of the linear deformations 14 a, 14 b,14 c, and 14 d are reinforced.

In FIGS. 2A and 2B, the number of the linear deformations constitutingone rib 14 is four. However, the number of the linear deformations maybe two or three. It is preferable to set the width of the rib 14 toaround 0.5 to 3 mm. It is preferable to set the height of the rib 14 toaround 0.5 to 3 mm.

In the present invention, the width of the rib 14 means the distancebetween the linear deformations, among the plurality of lineardeformations constituting one rib 14, which are most separated from eachother. In FIG. 2B, the distance w₂ between the linear deformations 14 cand 14 d in the outer side corresponds to the width of the rib 14. It ispreferable to set the distance w₁ between the linear deformations 14 aand 14 b in the inner side to be equal to or smaller than the distancew₂.

The height h of the rib 14 corresponds to the depth of the groove in theinner surface side of the film 11. If only two linear deformationsconstitute one rib 14 (for example, refer to FIG. 2 in Patent Document1: Japanese Unexamined Patent Application, First Publication No.H7-2260), the groove-shaped cross section can be formed by providing theliner deformations 14 a and 14 b of the mountain folds as the lineardeformation, and bending the film 11 instead of providing the linerdeformations 14 c and 14 d of the valley folds.

The cured portions 15 a and 15 b are formed by locally curing the film11. The cured portion 15 a is provided between the rib 14 and the flowpassage forming sealing portion 13 a, and the cured portion 15 b isprovided between the rib 14 and the flow passage forming sealing portion13 b. The cured portions 15 a and 15 b are disposed along the rib 14,and are planarly formed.

As a result, as shown in FIG. 2A, it is possible to make the spout 12almost flat when the bag is empty. Further, as shown in FIG. 5, bypiling some package bags 10 such that the positions of the ribs 14 arealternatively and slightly shifted, it is possible to reduce thebulkiness of the piled package bags 10.

There may be no gap between the rib 14 and the cured portions 15 a and15 b. However, it is preferable to ensure some gap in order to toleratesome degree of positional error when the rib 14 is formed bypress-molding an uncured portion between the cured portions 15 a and 15b.

Since the rib 14 is not cured, the rib 14 is bent more easily than thecured portions 15 a and 15 b. Therefore, when the package bag 10 isopened to spout the contents therefrom at the time of use, due to theweight of the contents, the cured portions 15 a and 15 b are separatedfrom each other with the flow passage forming sealing portions 13 a and13 b serving as a fulcrum, and the spout 12 is opened as shown in FIG.3B. That is, the body films 11 and 11 are spread out so as to be bentoutward of the package bag 10 in portions where the ribs 14 are formed.

Since the film 11 which forms the flow passage 13 includes the curedportions 15 a and 15 b, it is possible to maintain the opening state ofthe spout 12 even if the flow amount of the passing contents decreases.Further, since the rib 14 is provided at an approximately center of theflow passage 13, it is possible to increase the cross-sectional area ofthe opened flow passage 13.

As a result, it is possible to efficiently refill the contents from thepackage bag 10 to a container 1 by directing (or inserting) the openedspout 12 to an inlet 2 of the container 1 as shown in FIG. 3A.

As shown in FIG. 3A, if an outer edge shape of the flow passage formingsealing portion 13 a in the inlet 2 side protrudes toward a side surfaceof the inlet 2 by increasing the sealing width of the flow passageforming sealing portion 13 a, it becomes easier to fit the position ofthe spout 12 to the inlet 2 by abutting the spout 12 on the side surfaceof the inlet 2. Alternatively, as shown in FIG. 8, the outer edge shapeof the flow passage forming sealing portion 13 a may be recessed so asnot to make the flow passage forming sealing portion 13 a abut the inlet2.

In the present embodiment, it is preferable to form the cured portions15 a and 15 b by performing heating and cooling process on the film 11to crystallize at least a portion of the resin which constitutes thefilm 11. Alternatively, a method of locally applying ultraviolet curableresin to the film and curing the resin, or a method of adhering a moldedpiece to the film, may be employed as other methods of forming the curedportion. However, in the case of the present embodiment, since thematerial of the film 11 itself is cured, additional material is notrequired.

Crystalline polymer resin is known as resin which is capable of beingcrystallized by the heating and cooling process. The crystalline polymerresin has a high orderly molecular arrangement, and generally, has asmall side chain of polymer chain. Further, when melt-forming thecrystalline polymer resin, if the crystalline polymer resin is rapidlycooled to make it into a glass form, the transparency and theflexibility improve, but the crystallinity decreases. That is, thecrystallinity of the crystalline polymer resin of the film 11 beforeforming the cured portions 15 a and 15 b is low. When a predeterminedportion of the film 11 is heated to around the melting point (at leastover the glass-transition temperature) and then is cooled by spending,for example, one minute or more, it is possible to locally enhance thecrystallinity of the film 11, and it is thereby possible to form thecured portions 15 a and 15 b.

The known specific examples of the crystalline polymer resin includepolyethylene, polypropylene, polyethylene terephthalate, and isotacticpolystyrene. Among them, it is preferable to use resin whose meltingpoint is less than 200 degree C., such as polyethylene (HDPE, MDPE,LDPE, or LLDPE) and polypropylene (CPP or OPP), as the material of thefilm 11 of the package bag 10, since it is possible to easily performthe crystallizing process when manufacturing the bag.

FIG. 4 is an explanation drawing of a step of forming the rib 14 and thecured portions 15 a and 15 b in the film 11 when manufacturing thepackage bag 10 according to the present embodiment.

Regarding the order of a cured portion forming step and a rib formingstep, the cured portion forming step may be performed first as shown inFIG. 4, or the rib forming step may be performed first.

<Cured Portion Forming Step>

As shown in a D-part in FIG. 4, the film 11 is locally heated on atleast one side of a forming position of the rib 14 by means of a heater21 including a pair of heating molds 21 a and 21 b. In order to identifythe forming position of the rib 14 before forming the rib 14, it ispreferable to put a marking and the like at an appropriate position onthe film 11, and form the cured portions 15 a and 15 b using the markingas a standard.

Subsequently, as shown in an E-part in FIG. 4, the film 11 is locallycooled in the position which has been heated by the heater 21 in theD-part by means of a cooler 22 including a pair of cooling molds 22 aand 22 b.

By performing the heating and cooling process in this manner, it ispossible to form the cured portions 15 a and 15 b by crystallizing atleast a portion of the resin which constitutes the film 11.

The heating molds 21 a and 21 b and the cooling molds 22 a and 22 b aremolds whose shape corresponds to the shape of the cured portions 15 aand 15 b, and abut both surfaces of the film 11.

Among the cooling molds 22 a and 22 b, it is preferable to roughen anabutting surface of the cooling mold 22 a which abuts the outer surfaceof the film 11 through sandblast processing. As a result, it is possibleto perform roughening processing on outer surfaces of the cured portions15 a and 15 b of the film 11 by transferring the roughness of the moldto the outer surfaces of the cured portions 15 a and 15 b, and it isthereby possible to obtain an advantage such as preventing slipping. Thesandblast processing is performed using, for example, a material havingparticles whose particle diameter is around #10 to 100, and an abuttingsurface whose surface roughness is around 1 to 100 μm. Note that theabutting surface of the cooling mold 22 a may be roughened by otherroughening processing than the sandblast processing.

<Rib Forming Step>

As shown in an F-part in FIG. 4, pressing processing is performed on thefilm 11 by means of a presser (concave and convex molds) 23 including aconcave mold 23 a and a convex mold 23 b to form the rib 14 shown in aG-part in FIG. 4. As is described above, it is preferable to use theconcave mold 23 a and the convex mold 23 b without heating. Note that itis acceptable that the thickness of the film 11 in the portion where therib 14 is formed after the pressing processing is thinner than thethickness of the film 11 in the other portions. When the thickness ofthe film 11 in the portion where the rib 14 is formed is thin, the rib14 can be easily bent.

<Bag Manufacturing Step>

The film 11, in which the cured portions 15 a and 15 b and the rib 14have been formed at predetermined positions within an area where thespout 12 is to be formed, is delivered along rollers 24 and 25, and twofilms 11 are piled as shown in an H-part in FIG. 4. Further, the bottomfilm 16 folded in half is supplied between the body films 11 and 11. Abag manufacturing step is performed by using conventionally knownmethods.

For example, the package bag 10 is manufactured by forming sealingportions such as the side edge sealing portions 11 a and 11 b, the flowpassage forming sealing portions 13 a and 13 b, and the bottom sealingportion 16 b, and cutting it along the outer shape of the bag.

If a notch and the like are formed in the edge of the package bag 10, acutter, a punching machine, or the like is used to respective packagebag 10 after separation to form the notch and the like at a desiredposition. The notch and the like may be simultaneously formed whenforming the outer shape of the package bag.

<Opening Assisting Line Forming Step>

The opening assisting line 12 a is formed by half-cutting the film by,for example, irradiating a laser. If laser irradiation is performed soas to intersect the rib 14 as the package bag 100 in FIG. 8, the focusof the laser irradiation may be moved along a surface shape of the rib14.

While the present invention have been explained based on a preferredembodiment, the invention is not to be considered as being limited bythe foregoing embodiment, and various modifications can be made withoutdeparting from the scope of the present invention.

In FIG. 1, an example of providing the cured portions 15 a and 15 b inthe both sides of the rib 14 is described. However, the cured portionmay be provided in only one side of the rib 14. In this case, it ispreferable to provide the cured portion 15 a at a position where thecured portion 15 a is positioned under the rib 14 at the time ofspouting as shown in FIG. 3A. Further, as shown in FIG. 6, a pluralityof ribs 14 may be provided in rows in the one film 11.

Further, as shown in FIG. 7, the positions of the ribs 14 may be shiftedon the front and back sides of the bag. By shifting the positions of theribs 14 on the front and back sides of the bag, when piling some packagebags 10, it is possible to reduce the bulkiness of the piled packagebags 10 without alternatively shifting the positions of the package bags10 as shown in FIG. 5

The flow passage 13 in FIG. 1 is curved toward the outside in the widthdirection of the package bag 10 (that is, toward the left in FIG. 1)such that the angle of the flow passage 13 with respect to the widthdirection of the package bag 10 closes to 0°, and the rib 14 is formedin an arc shape along the flow passage 13. However, the shape of thespout and the direction of the flow passage are not particularly limitedand can be appropriately set in the viewpoint of easier spouting andmanufacturing. For example, the flow passage of the spout may bestraight. Alternatively, the tip end portion of the spout may protrudefrom one side of the package bag.

The bottom film 16 is not essential, and the present invention can beapplied to a package bag constituted by a planar bag such as athree-side sealed bag or a four-side sealed bag.

Further, as shown in a package bag 200 in FIG. 9, the rib 14 may bedisposed at a predetermined position. Note that in the package bag 200shown in FIG. 9, the same constituent elements as those of the packagebag 10 shown in FIG. 1 are designated by the same reference numerals.

The body films 11 and 11 are formed in a substantially rectangularshape. Among the pair of flow passage forming sealing portions 13 a and13 b, one flow passage forming sealing portion 13 b is provided on aside of an upper side (a first side) 11 c of the film 11, and the otherflow passage forming sealing portion 13 a is provided on a side of alateral side (a second side) 11 d adjacent to the upper side 11 c of thefilm 11. At least one rib 14 is disposed on an intersection point Xbetween a line L1 and a line L2, the line L1 passing through a position13 d of the flow passage forming sealing portion 13 b which is theclosest to a lower side (a third side) 11 e opposite to the upper side11 c and extending substantially parallel to the lower side 11 e, theline L2 passing through a position 13 e of the flow passage formingsealing portion 13 a which is the closest to the other lateral side (afourth side) 11 f opposite to the lateral side 11 d and extendingsubstantially perpendicular to the lower side 11 e.

The spout 12 tends to occlude at a portion of the intersection point Xbetween the line L1 and the line L2 when spouting the contents. In thepackage bag 200 shown in FIG. 9, since the rib 14 is disposed on theintersection point X, it is possible to prevent the occlusion of thespout 12, and to rapidly discharge the contents.

INDUSTRIAL APPLICABILITY

The present invention is suitably applied to a package bag in whichfluid contents such as a liquid, powders, grains, or mixtures thereof,are filled.

REFERENCE SIGNS LIST

-   10, 100, 200: package bag-   11: body film (film)-   11 a, 11 b: side edge sealing portion-   11 c: upper side (first side)-   11 d: lateral side (second side)-   11 e: lower side (third side)-   11 f: lateral side (fourth side)-   12: spout-   12 a: opening assisting line-   13: flow passage-   13 a, 13 b: flow passage forming sealing portion-   14: groove rib-   15 a, 15 b: cured portion

1. A manufacturing method of a package bag including: a spout defined bya pair of flow passage forming sealing portions which are formed bysealing two films at both side portions of a flow passage; a groove ribformed so as to protrude outward of the film and extend along the flowpassage; and a cured portion formed on at least one side of the rib bycrystallizing at least a portion of a resin constituting the film, themanufacturing method comprising: a cured portion forming step of formingthe cured portion on at least one side of a forming position of the ribby crystallizing at least a portion of the resin constituting the filmby heating and cooling the film; and a rib forming step of forming therib by pressing the film using concave and convex molds.
 2. Themanufacturing method of a package bag according to claim 1, wherein therib has a width of 0.5 to 3 mm and a height of 0.5 to 3 mm.
 3. Themanufacturing method of a package bag according to claim 1, wherein inthe rib forming step, the rib is formed without heating.
 4. Themanufacturing method of a package bag according to claim 1, wherein inthe cured portion forming step, the film is cooled by molds, whose shapecorresponds to the shape of the cured portion, abutting both surfaces ofthe film, and a roughening processing is performed on an outer surfaceof the cured portion of the film by using a mold having an abuttingsurface which abuts an outer surface of the film and on which asandblast processing is performed.
 5. The manufacturing method of apackage bag according to claim 1, further comprising a step of providingan opening assisting line which intersects the rib.
 6. A package bagcomprising: a spout which is defined by a pair of flow passage formingsealing portions which are formed by sealing two films at both sideportions of a flow passage; a groove rib which is formed so as toprotrude outward of the film and extend along the flow passage; and acured portion which is formed on at least one side of the rib bycrystallizing at least a portion of a resin constituting the film. 7.The package bag according to claim 6, wherein the rib has a width of 0.5to 3 mm and a height of 0.5 to 3 mm.
 8. The package bag according toclaim 6, further comprising an opening assisting line which is providedso as to intersect the rib.
 9. The package bag according to claim 6,wherein an outer surface of the cured portion of the film is roughened.10. The package bag according to claim 6, wherein: the film is formed ina substantially rectangular shape; among the pair of flow passageforming sealing portions, one flow passage forming sealing portion isprovided on a first side of the film, and the other flow passage formingsealing portion is provided on a second side of the film adjacent to thefirst side; and at least one of the ribs is disposed on an intersectionpoint between a line passing through a position of the flow passageforming sealing portion on the first side which is the closest to athird side opposite to the first side and extending substantiallyparallel to the third side, and a line passing through a position of theflow passage forming sealing portion on the second side which is theclosest to a fourth side opposite to the second side and extendingsubstantially perpendicular to the third side.
 11. The manufacturingmethod of a package bag according to claim 2, wherein in the rib formingstep, the rib is formed without heating.
 12. The manufacturing method ofa package bag according to claim 2, wherein in the cured portion formingstep, the film is cooled by molds, whose shape corresponds to the shapeof the cured portion, abutting both surfaces of the film, and aroughening processing is performed on an outer surface of the curedportion of the film by using a mold having an abutting surface whichabuts an outer surface of the film and on which a sandblast processingis performed.
 13. The manufacturing method of a package bag according toclaim 3, wherein in the cured portion forming step, the film is cooledby molds, whose shape corresponds to the shape of the cured portion,abutting both surfaces of the film, and a roughening processing isperformed on an outer surface of the cured portion of the film by usinga mold having an abutting surface which abuts an outer surface of thefilm and on which a sandblast processing is performed.
 14. Themanufacturing method of a package bag according to claim 2, furthercomprising a step of providing an opening assisting line whichintersects the rib.
 15. The manufacturing method of a package bagaccording to claim 3, further comprising a step of providing an openingassisting line which intersects the rib.
 16. The manufacturing method ofa package bag according to claim 4, further comprising a step ofproviding an opening assisting line which intersects the rib.
 17. Thepackage bag according to claim 7, further comprising an openingassisting line which is provided so as to intersect the rib.
 18. Thepackage bag according to claim 7, wherein an outer surface of the curedportion of the film is roughened.
 19. The package bag according to claim8, wherein an outer surface of the cured portion of the film isroughened.
 20. The package bag according to claim 7, wherein: the filmis formed in a substantially rectangular shape; among the pair of flowpassage forming sealing portions, one flow passage forming sealingportion is provided on a first side of the film, and the other flowpassage forming sealing portion is provided on a second side of the filmadjacent to the first side; and at least one of the ribs is disposed onan intersection point between a line passing through a position of theflow passage forming sealing portion on the first side which is theclosest to a third side opposite to the first side and extendingsubstantially parallel to the third side, and a line passing through aposition of the flow passage forming sealing portion on the second sidewhich is the closest to a fourth side opposite to the second side andextending substantially perpendicular to the third side.